How to Measure Your Kitchen for New Cabinets

Accurate measurements are the foundation of every kitchen remodel. A cabinet run that is half an inch too long will not fit, and one that is an inch too short leaves a gap you have to hide with a filler. This guide walks through how to measure a kitchen for cabinets the way designers and installers do it, so the plan you build on paper matches the room you actually have.

Tools you will need

You do not need specialist equipment, but a few tools make the job faster and more reliable:

• A 25 ft (7.5 m) steel tape measure with a stiff blade, so you can reach across a room without it sagging.
• A laser distance measurer (optional but helpful) for long walls and ceiling heights.
• A 4 ft (1.2 m) level and a framing square for checking plumb, level and corners.
• Graph paper, a pencil and an eraser, or a tablet sketch app.
• Painter's tape for marking reference heights on walls.
• A helper, if possible. Two people holding a tape produce noticeably better numbers than one.

Pick one unit system and stick with it. If you work in inches, record to the nearest 1/8 in; if you work in metric, record to the nearest millimetre. Mixing units on one sketch is one of the most common sources of error.

Step 1: Draw a rough sketch of the room

Before you measure anything, draw a bird's-eye outline of the kitchen. It does not need to be to scale. Include:

• Every wall, numbered clockwise starting from the entry door.
• Doors, windows and openings to other rooms.
• Existing appliances, the sink and any island or peninsula.
• Radiators, vents, beams, bulkheads and chases.

Leave plenty of white space around the outline so you have room to write dimensions. A cramped sketch leads to numbers you cannot read later.

Step 2: Measure each wall at three heights

Walls are rarely perfectly straight, and corners are rarely exactly 90 degrees. Measure every wall from corner to corner at three heights:

Use the smallest of the three readings when planning cabinet runs. If the numbers differ by more than about 1/4 in (6 mm), note it on the sketch; it usually means a bowed wall or an out-of-square corner, and your installer will want to know.

Measure along the wall surface, not the baseboard. If you are removing baseboards or tiles, measure from the bare wall or note the thickness to subtract.

Step 3: Measure ceiling height and soffits

Measure floor-to-ceiling height in several places, including each corner and the middle of each wall. Floors and ceilings often slope, and a difference of 1/2 in (13 mm) across a room can determine whether a tall pantry or a stacked upper cabinet fits.

If the kitchen has a soffit (a boxed-in bulkhead above the upper cabinets), record:

• Its height from the floor to the underside.
• Its depth from the wall.
• Its length along each wall.
• Whether you plan to remove it, and what might be inside (ducts, pipes or wiring).

Step 4: Locate windows, doors and openings

For every window and door, take measurements that include the trim (casing), because cabinets cannot overlap it:

1. Distance from the nearest corner to the outside edge of the trim.
2. Width of the opening including trim.
3. For windows, height from the floor to the bottom of the trim (the sill or apron) and to the top of the trim.
4. Trim width and how far it projects from the wall.
5. Which way each door swings, and whether the swing crosses a future cabinet or appliance.

Write running dimensions (corner to each edge) as well as the individual widths. Running dimensions prevent small errors from accumulating as you add up segments.

Step 5: Mark utilities

Plumbing, gas and electrical locations drive the layout, and moving them adds cost. Measure from the nearest corner and from the floor to the centre of each item:

• Sink supply lines and drain (and the dishwasher connection if separate).
• Gas line for a range or cooktop.
• Electrical outlets, switches and dedicated circuits for the range, microwave, refrigerator and dishwasher.
• Range hood vent location, through the wall or ceiling.
• Heating and cooling vents, radiators and thermostats.
• Water line for a refrigerator ice maker.

A photo of each wall with a tape measure visible is a cheap way to capture context you may forget later.

Step 6: Check for out-of-square corners and uneven floors

Corners

Use the 3-4-5 method to check whether a corner is square. Measure 3 ft (or 300 mm) along one wall and mark it, then 4 ft (400 mm) along the other wall and mark it. The diagonal between the marks should be exactly 5 ft (500 mm). If it is longer, the corner is wider than 90 degrees; if shorter, it is tighter. For more accuracy, scale up to 6-8-10.

Floors

Lay a long level along the floor where the base cabinets will sit and find the high point. Cabinets are leveled up from the highest spot, so knowing how much the floor drops elsewhere tells your installer how much shimming to expect. Note the deviation on your sketch.

Walls

Hold the level vertically against each wall. Walls that lean out of plumb affect how tall cabinets and wall cabinets sit, and may need scribing at the edges.

Step 7: Record appliance specifications

Do not plan around the appliance you have today if you are replacing it. Download the installation guide for each new appliance and record:

• Width, height and depth, including handles.
• Required cutout dimensions for built-in or panel-ready models.
• Door swing clearance and whether the door needs space to open past 90 degrees.
• Required side clearances, ventilation gaps and utility locations.

Typical widths are a useful starting point, but they vary by model:

Always confirm against the manufacturer's spec sheet. For how these widths map to cabinet boxes, see our guide to standard kitchen cabinet sizes.

Step 8: Transfer measurements into a plan

Once you have a complete sketch, redraw it to scale or enter it into planning software. Check that the wall lengths you recorded add up: the running dimensions along a wall should equal the overall corner-to-corner length. If they do not, re-measure before ordering anything.

OpenKitchen3D, currently in development, is being designed around this workflow. You will be able to scan a room or enter dimensions, correct any measurement, and lay out parametric cabinet runs that snap to walls and reflow when a dimension changes. Millimetres are the internal unit, but the goal is that you can work in whichever units you measured in. Scans and drawings are a starting point; final measurements should always be field-verified before fabrication or ordering.

If you have a LiDAR-equipped iPhone or iPad, a scan can speed up the rough capture. See how to scan a kitchen with iPhone LiDAR for tips and limits.

Common mistakes to avoid

• Measuring only once. Take each critical measurement twice, ideally by two people.
• Ignoring trim. Window and door casing eats into usable wall length.
• Rounding up. Always round down when in doubt. A small gap can be filled; an oversized cabinet cannot be shrunk.
• Forgetting the corners. Blind corners and out-of-square walls need fillers so doors and drawers can open.
• Skipping clearance planning. Measurements should feed directly into aisle and landing-space checks. Our kitchen clearances guide covers the common guidelines.
• Using the old appliance size. New models are often deeper or taller than the units they replace.
• Measuring over obstructions. Measure the wall itself, then note baseboards, tile and other surface items separately.

Frequently asked questions

How accurate do kitchen measurements need to be?

Record measurements to the nearest 1/8 in (about 3 mm). Cabinet runs are usually planned with small fillers at the ends to absorb minor variation, but larger errors can mean a cabinet does not fit at all. When in doubt, re-measure and plan to the smallest reading.

Should I measure with old cabinets still installed?

Yes, you can, but measure the walls themselves wherever possible, such as above the countertop and inside open cabinets. Old cabinets and countertops can hide bowed walls and out-of-square corners. Plan to re-check key dimensions once the room has been demolished.

Why measure each wall at multiple heights?

Walls are seldom perfectly straight or plumb, so a single reading can be misleading. Measuring near the floor, at countertop height and at wall cabinet height reveals bows and leans. Planning to the smallest reading helps make sure cabinets fit along the whole run.

Do I still need to measure by hand if I scan the room?

Yes. A phone or tablet scan is a fast way to capture the overall shape of a room, but it is not precise enough to order cabinets from on its own. Treat the scan as a starting point and confirm critical dimensions, such as wall lengths and opening positions, with a tape measure.

What should I measure for appliances?

Measure the appliance you are actually installing, using the manufacturer's installation guide rather than the old unit. Record overall width, height and depth with handles, required cutouts, side clearances and door swing space. Note utility locations so the plan keeps gas, water and power where the new appliance needs them.